requiring students to buy cookies with cash (but allowing them to use lunch credits for fruit) increased fruit sales by 71 percent

using smaller bowls decreased breakfast cereal portions by 24 percent

keeping ice cream in a closed-top freezer reduced the number of takers by up to 30 percent

This isn’t rocket science. There’s a reason moms leave fruit in a bowl on the kitchen table and cookies in a closed jar. Grocery stores know that people pick up stuff as they’re waiting at the cash register. Fast food restaurants never forget to ask if you want fries with that. And plenty of other industries – from hospitals to auto manufacturers – have improved health outcomes through better engineering.

As I’ve documented in some detail, it’s not easy to overhaul menus in school cafeterias that are charged with magically turning pennies into healthy meals. And it’s important to advocate for nutrition policies and adequate spending that will help in those efforts. But these seem like easy fixes that would cost schools little to nothing and could make a real difference in fighting childhood obesity. And best of all, students aren’t likely to notice how much better they’re eating.